tdk has a excellent reference doc concerning decoupling.

i think X7R 20% is a good standard for the things you need to do.

the dev /proto board is using a range of overscaled items.  I hear that bitmine had some issues with their protoboard upfront regarding  decoupling & thermal issues.

ref :

http://www.digikey.co.il/Web%20Export/Supplier%20Content/TDK_445/PDF/TDK_ESR_Controlled_MLCCs.pdf?redirected=1
http://www.youtube.com/watch?feature=player_embedded&v=Rrgdi843Dec
http://www.pcbcarolina.com/images/01_pcb_power_decoupling_myths_debunked.pdf
http://www.cdnusers.org/community/allegro/Resources/resources_pcbsi/si/tp_zhen_capacitors.pdf

board is built (1 hour part preperation time; 4h30 picking parts and reflowing)

when powering up the board I got the same problem as zipiju reported (3.3V short)

using flux i scanned all the asic's ; and noticed some shorts ; fixed!

power up the board ; RED led powered up ; bank 0 power rails OK ; bank 1 power rail  1V not ok (0V)

refluxed asics on bank 1 ; problem is that power rail 1V is NOT stable and asics run SUPER hot! (also the IR and the power inductor) ; anyone got any idea why or where to look ? )

@zipiju : still alive ? Hope you didn't put you on vfib on 3.3V rail 

is er een site met evt contactinfo ?

we moeten NU Belgie bitcoin-aware maken

since 98% are smd; a tape would be better

i'm happy to provide a kit option ; all the parts ; solder stencil etc ; in a group-buy way ... best would be that we can adjust pricing by total quantity ordered; it should be pre-funded in order to be sure that we get the sharpest price and don't have people bailing in & out the buy.

people who fund first at eg. 50 pcs will get a refund if we hit a 100 target, etc .. etc

last but not least, since we are looking into opensource and hardwork of some people; we should tip/fund/support the community! 

i'm located in Belgium, Europe ; shipping to EU would be easy.  For the AMERICAS i think it is best to have somebody that would take that part of the world.

anybody else idea's and thoughts about this ? 

if people are interested in a KIT verison .. maybe it's not a bad idea to pre-order kits .. and to bring the part prices down ..

what should the KIT contain ?

pcb + parts + avalons + cooling fan + heatsink

or also other parts such as a PIC programmer.. etc..

Zipiju

should i ingore the drc errors on the PIC & IR3895 in kicad when checking ?

@Zipiju : i noticed you made changes to github repo ; and news about the progress ?  Are you still using the klondike board as it exists for the avalon gen 1?

it's 25A ; putting two on the board makes 50A ; for 16 chips at 2000ma draw ; enough buffer to overclock ...

PCB will change .. but might be worth it... i'm happy to experiment with it though!

Hi

i'm from belgium too

check this video

http://www.youtube.com/watch?v=Piasa1WgHjA

@Zipiju : can these mods be "copied" to the USB version with a single chip?

pretty simple


 bitcoind importprivkey "yourprivatekeypair"

or via the debug console just

      importprivkey "yourprivatekeypair"

try it first with a bogus wallet

I would recommend multibit, but please don't freak out if transactions go crazy.

Use the reset transactions option to rebuild your block; and restart afterwards.


bitcoin-qt takes a long time to get up and running, it needs to sync all the blocks.

you need to EXPORT your key .

copying he files is NO good backup!!!

this is the CORRECT way


    Bitcoin-Qt
        Help -> Debug window -> Console
            walletpassphrase {passphrase} {timeout}
            dumpprivkey {bitcoinaddress}

Hi

somebody on IRC pointed me to this video on youtube

I think it contains valuable information about BTC (for newbies)

Please don't forget ; Billy is owner of BTCCHINA and presentation was made BEFORE China's regulation.

Also ignore the promo-talk

http://www.youtube.com/watch?v=Piasa1WgHjA

Enjoy!